Fosaprepitant

Fosaprepitant blocks the actions of chemicals in the body that trigger nausea and vomiting.

Fosaprepitant is used together with other medications to prevent nausea and vomiting that may be caused by chemotherapy.

Fosaprepitant will only prevent nausea and vomiting. It will not treat nausea or vomiting that you already have.

Fosaprepitant may also be used for purposes not listed in this medication guide.

You should not use this medication if you also take pimozide. Using these drugs together can cause unwanted or dangerous effects.

You should not use this medication if you are allergic to fosaprepitant, aprepitant (oral Emend), or polysorbate 80, or if you also take pimozide.

Using fosaprepitant while you are also taking pimozide can cause unwanted or dangerous effects.

To make sure fosaprepitant is safe for you, tell your doctor if you have liver disease.

FDA pregnancy category B. Fosaprepitant is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Fosaprepitant can make birth control pills less effective. This effect can last for up to 28 days after your last dose of fosaprepitant. Ask your doctor about using non-hormonal birth control (condom, diaphragm with spermicide) to prevent pregnancy while you are receiving fosaprepitant, and for at least 1 month after your treatment ends.

It is not known whether fosaprepitant passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Fosaprepitant is injected into a vein through an IV. A healthcare provider will give you this injection.

The first dose of fosaprepitant is usually given 30 minutes before your chemotherapy treatment begins.

You may also be given other medicines, including aprepitant capsules (Emend), to further help prevent nausea and vomiting.

Fosaprepitant is not for long-term use.

If you also take warfarin (Coumadin, Jantoven), you may need extra "INR" or prothrombin time tests after you have received fosaprepitant.

Since this medication is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

Get emergency medical help if you have signs of an allergic reaction: hives, rash, itching, skin sores or peeling; warmth or tingly feeling; trouble breathing or swallowing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• pain, redness, swelling, or bruising where the medicine was injected;

• a light-headed feeling, like you might pass out;

• pain or burning when you urinate; or

• low white blood cell counts--fever, swollen gums, mouth sores, skin sores, cold or flu symptoms, pale skin, easy bruising, unusual bleeding.

Common side effects may include:

• weakness, tired feeling;

• diarrhea;

• indigestion; or

• pain in your arms or legs.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

• If you need to store fosaprepitant at home, talk with your doctor, nurse, or pharmacist about how to store it.

Following oral administration of aprepitant 125 mg on day 1 and 80 mg once daily on days 2 and 3 to patients with mild hepatic impairment (Child-Pugh score 5 to 6), the AUC of aprepitant was 11% lower on day 1 and 36% lower on day 3 (compared to healthy subjects); in patients with moderate hepatic impairment (Child-Pugh score 7 to 9), the AUC of aprepitant was 10% higher on day 1 and 18% higher on day 3 (compared to healthy subjects). These differences are not considered clinically meaningful.

Prevention of chemotherapy-induced nausea/vomiting:

Highly emetogenic chemotherapy: IV: 150 mg ~30 minutes prior to chemotherapy on day 1 only (in combination with a 5-HT3 antagonist on day 1 only and dexamethasone on days 1 to 4 [reduce dexamethasone dose by 50% on days 1 and 2])

Moderately emetogenic chemotherapy: IV: 150 mg ~30 minutes prior to chemotherapy on day 1 only (in combination with a 5-HT3 antagonist and dexamethasone on day 1 [reduce dexamethasone dose by 50%])

Infuse over 20 to 30 minutes ~30 minutes prior to chemotherapy

Aprepitant: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

ARIPiprazole: CYP3A4 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy

Astemizole: Fosaprepitant may increase the serum concentration of Astemizole. The active metabolite aprepitant is likely responsible for this effect. Avoid combination

Bosentan: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Cisapride: Fosaprepitant may increase the serum concentration of Cisapride. The active metabolite aprepitant is likely responsible for this effect. Avoid combination

Conivaptan: May increase the serum concentration of CYP3A4 Substrates. Avoid combination

Contraceptives (Estrogens): Fosaprepitant may decrease the serum concentration of Contraceptives (Estrogens). The active metabolite aprepitant is likely responsible for this effect. Management: Alternative or additional methods of contraception should be used both during treatment with fosaprepitant or aprepitant and for at least one month following the last fosaprepitant/aprepitant dose. Consider therapy modification

Contraceptives (Progestins): Fosaprepitant may decrease the serum concentration of Contraceptives (Progestins). The active metabolite aprepitant is likely responsible for this effect. Management: Alternative or additional methods of contraception should be used both during treatment with aprepitant or fosaprepitant and for at least one month following the last aprepitant/fosaprepitant dose. Consider therapy modification

Corticosteroids (Systemic): Fosaprepitant may increase the serum concentration of Corticosteroids (Systemic). The active metabolite aprepitant is likely responsible for this effect. Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP3A4 Inhibitors (Moderate): May decrease the metabolism of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inhibitors (Strong): May decrease the metabolism of CYP3A4 Substrates. Consider therapy modification

CYP3A4 Substrates: Fosaprepitant may increase the serum concentration of CYP3A4 Substrates. Monitor therapy

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates. Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dasatinib: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

DilTIAZem: Fosaprepitant may increase the serum concentration of DilTIAZem. The active metabolite aprepitant is likely responsible for this effect. DilTIAZem may increase the serum concentration of Fosaprepitant. Specifically, diltiazem may increase the concentration of the active metabolite aprepitant. Monitor therapy

Dofetilide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Dofetilide. Monitor therapy

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates. Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification

Flibanserin: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Flibanserin. Monitor therapy

Fusidic Acid (Systemic): May increase the serum concentration of CYP3A4 Substrates. Avoid combination

HYDROcodone: CYP3A4 Inhibitors (Weak) may increase the serum concentration of HYDROcodone. Monitor therapy

Idelalisib: May increase the serum concentration of CYP3A4 Substrates. Avoid combination

Ifosfamide: Fosaprepitant may increase the serum concentration of Ifosfamide. Specifically, concentrations of the toxic metabolites of ifosfamide may increase. Monitor therapy

Lomitapide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Lomitapide. Management: Patients on lomitapide 5 mg/day may continue that dose. Patients taking lomitapide 10 mg/day or more should decrease the lomitapide dose by half. The lomitapide dose may then be titrated up to a max adult dose of 30 mg/day. Consider therapy modification

MiFEPRIStone: May increase the serum concentration of CYP3A4 Substrates. Management: Minimize doses of CYP3A4 substrates, and monitor for increased concentrations/toxicity, during and 2 weeks following treatment with mifepristone. Avoid cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus. Consider therapy modification

Mitotane: May decrease the serum concentration of CYP3A4 Substrates. Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification

Netupitant: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

NiMODipine: CYP3A4 Inhibitors (Weak) may increase the serum concentration of NiMODipine. Monitor therapy

Palbociclib: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

PARoxetine: May decrease serum concentrations of the active metabolite(s) of Fosaprepitant. Fosaprepitant may decrease the serum concentration of PARoxetine. Monitor therapy

Pimozide: Fosaprepitant may increase the serum concentration of Pimozide. The active metabolite aprepitant is likely responsible for this effect. Avoid combination

RifAMPin: May decrease the serum concentration of Fosaprepitant. More specifically, rifampin may decrease concentrations of the active metabolite aprepitant. Monitor therapy

Sarilumab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Simeprevir: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

Sirolimus: Fosaprepitant may increase the serum concentration of Sirolimus. Monitor therapy

St John's Wort: May decrease the serum concentration of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Stiripentol: May increase the serum concentration of CYP3A4 Substrates. Management: Use of stiripentol with CYP3A4 substrates that are considered to have a narrow therapeutic index should be avoided due to the increased risk for adverse effects and toxicity. Any CYP3A4 substrate used with stiripentol requires closer monitoring. Consider therapy modification

Terfenadine: Fosaprepitant may increase the serum concentration of Terfenadine. The active metabolite aprepitant is likely responsible for this effect. Avoid combination

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

TOLBUTamide: Fosaprepitant may decrease the serum concentration of TOLBUTamide. Monitor therapy

Warfarin: Fosaprepitant may decrease the serum concentration of Warfarin. The active metabolite aprepitant is likely responsible for this effect. Monitor therapy

Adverse events were not observed in animal reproduction studies for aprepitant. Efficacy of hormonal contraceptive may be reduced; alternative or additional methods of contraception should be used both during treatment with fosaprepitant or aprepitant and for at least 1 month following the last fosaprepitant/aprepitant dose.